Lower frame midrails in an automotive vehicle support the central part of an automotive chassis and provide a cantilevered support for the rear bumper assembly. Conventionally, the rear bumper assembly would include a transverse bumper beam, lower frame rails and appropriate attachment brackets for connecting the bumper beam to the lower frame rails and the lower frame rails to the midrails. The rear shock tower support members are mounted on top of the midrails, conventionally in a cantilevered manner off of a single fabricated rail structure.
Conventional automotive frame designs are formed from fabricated steel components that are provided with many reinforcements affixed to the frame to accommodate the attachment of subframe components to the frame structure. The reinforcements permit the localized loads coming from subframe structures or other secondary structures to be transmitted into the frame structure without distortion of the frame. The formation of frame structure, such as the lower midrail frame structure from tubular hydroformed components, provides unique opportunities for the support and mounting of subframe components from a hydroformed frame structure.
Conventional clamps and brackets for attaching apparatus to frame structure can be found in U.S. Pat. No. 1,697,498, issued to Rollie B. Rageol on Jan. 1, 1929; and in U.S. Pat. No. 2,248,344, issued to Louis J. Epps on Jul. 8, 1941, where structure is mounted to tubular bumper components; in U.S. Pat. No. 2,270,533, issued to Joseph F. Knutte on Jan. 20, 1942; and in U.S. Pat. No. 5,215,343, issued to William C. Fortune on Jun. 1, 1993, where components are mounted to non-tubular bumper components. Clamping frame components together with couplings that become welded to the tubular frame members is taught in U.S. Pat. No. 6,022,070, issued to Toshiro Ashina, et al on Feb. 8, 2000.
Hollow tubular members are used as reinforcements for an automotive frame structure in U.S. Pat. No. 4,986,597, issued to Edvin L. Clausen on Jan. 22, 1991. Hydroformed automotive frame components are disclosed in U.S. Pat. No. 6,302,478, issued to Federico G. Jackel, et al on Oct. 16, 2001. In the Jackel frame structure, the hydroformed components are manufactured with flanges that will at least partially encompass a frame or subframe part to be joined thereto to facilitate the welding of the two components through the interaction with the flange components.
It would be desirable to provide an apparatus for the mounting of subframe structural components to the lower frame midrails. Since the lower frame midrails are to be formed from a pair of vertically oriented, but horizontally disposed tubular components, a unique apparatus to be particularly adaptable for use in conjunction with the lower frame rail structure of an automobile that are particularly adaptable to manufacturing through hydroforming processes and which can be utilized to provide a stable support for the rear shock tower.